ISmRandomForest.Forest

Syntax

Description

The Forest property returns an array of trees.

Comments

To determine the number of tree in random forest, use the ISmRandomForest.ForestSize property.

Example

Add a link to the Stat system assembly.

Sub UserProc;
Var
    rf: SmRandomForest;
    Y, OrdX: Array[16] Of Integer;
    X: Array[16] Of Double;
    res, i: Integer;
    Explanatories: ISlSeries;
    Explan: ISlSerie;
    ExplOrdered: ISlSeriesInt;
    ExpOrd: ISlSerieInt;
    Forest: IBinaryTreeForest;
    TreeNode: IBinaryTreeNode;
Begin
    rf := New SmRandomForest.Create;
    // Set explained series
    Y[00] := 0; Y[08] := 1;
    Y[01] := 1; Y[09] := 0;
    Y[02] := 0; Y[10] := 2;
    Y[03] := 2; Y[11] := 2;
    Y[04] := 1; Y[12] := 1;
    Y[05] := 1; Y[13] := 2;
    Y[06] := 2; Y[14] := 0;
    Y[07] := 1; Y[15] := 2;
    rf.Dependent.Value := Y;
    // Set explained series (ordinal)
    OrdX[00] := 0; OrdX[08] := 0;
    OrdX[01] := 0; OrdX[09] := 1;
    OrdX[02] := 0; OrdX[10] := 1;
    OrdX[03] := 0; OrdX[11] := 1;
    OrdX[04] := 0; OrdX[12] := 1;
    OrdX[05] := 0; OrdX[13] := 1;
    OrdX[06] := 0; OrdX[14] := 1;
    OrdX[07] := 0; OrdX[15] := 1;
    ExplOrdered := rf.ExplanatoriesOrdered;
    ExplOrdered.Clear;
    ExpOrd:= ExplOrdered.Add;
    ExpOrd.Value := OrdX;
    // Set explanatory series (quantitative)
    X[00] := 34.13; X[08] := 29.27;
    X[01] := 21.52; X[09] := 23.39;
    X[02] := 25.43; X[10] := 28.28;
    X[03] := 43.42; X[11] := 43.55;
    X[04] := 40.19; X[12] := 44.80;
    X[05] := 24.97; X[13] := 23.23;
    X[06] := 20.57; X[14] := 37.14;
    X[07] := 30.81; X[15] := 27.44;
    Explanatories := rf.ExplanatoriesContinuous;
    Explanatories.Clear;
    Explan := Explanatories.Add;
    Explan.Value := X;
    // Number of attributes
    rf.NumberOfPredictors := 2;
    // Trees size
    rf.TreeSizeSpecification.MaximumNumberOfLevels := 10;
    rf.TreeSizeSpecification.MinimumNumberOfCases := 2;
    // Perform calculation and display error  messages
    res:=rf.Execute;
    If (res = 0) Then
        Forest := rf.Forest;
        Debug.WriteLine("Number of trees in ensemble: "+Forest.Count.ToString);
        For i := 0 To Forest.Count - 1 Do
            TreeNode := Forest.Item(i);
            Debug.WriteLine("Tree "+(i+1).ToString);
            Debug.WriteLine(" Root node");
            print(TreeNode);
        End For;
        Else
            Debug.WriteLine(rf.Errors);
    End If;
End Sub UserProc;
…
Sub print(node: IBinaryTreeNode);
Begin
    Debug.WriteLine("  Number of node in tree: " + node.NodeIndex.ToString);
    Debug.WriteLine("  Improvement coefficient: " + node.Improvement.ToString);
    If(node.LeftNode <> Null) Then
        Debug.WriteLine(" Left branch");
        print(node.LeftNode);
    End If;
    If(node.RightNode <> Null) Then
        Debug.WriteLine(" Right branch");
        print(node.RightNode);
    End If;
End Sub print;

After executing the example the console window displays:

Number of trees in ensemble.
Information about trees in ensemble:

Tree root node.
Left branch of tree.
Right branch of tree.